Try to fix a PDF that will not open properly
When a PDF refuses to open or complains about errors, its internal index is often damaged. This tool rebuilds that structure in your browser and reports what it found.
- Files never leave your browser.
- No account needed
- No watermark added
- Works on any device
How it works
Step 1: Choose or drop the PDF that will not open or shows errors.
Step 2: Select Repair PDF and wait for the rebuild to finish.
Step 3: Read the report to see whether problems were found and fixed.
Step 4: Download the repaired file and page through it to check the content.
What repairing a PDF actually does
Every PDF carries a cross-reference table, an index that tells the viewer where each object in the file lives. Interrupted downloads, faulty exports and mail gateways that cut or alter attachments can truncate or scramble that index. The viewer then reports an error, shows blank pages or refuses to open the file at all.
The repair tool re-reads the objects it can find using QPDF, a well-known PDF library compiled to WebAssembly so it runs in your browser, and writes a fresh file with a new cross-reference table and rebuilt object streams. It reports whether QPDF found problems and fixed them.
It can recover many files that will not open, but it cannot invent data that is missing. A file cut off halfway comes back with the pages that survived, not the ones that were never saved.
Why use this tool
Runs in your browser
The damaged file is repaired on your device, so a private document does not have to be sent to anyone to be rescued.
A report, not a guess
The tool tells you whether QPDF found problems and fixed them, so you know if the new file is worth trusting.
Fixes structure, keeps content
Pages, text and images are carried over as they are; only the internal index and object layout are rebuilt.
No account, no watermark
Try as many files as you like. The result carries no branding.
Common uses
A download that stopped halfway
A large report fetched over a weak connection now opens with a damaged-file message. Rebuilding the index often brings back the pages that did arrive.
An attachment mangled by email
Some gateways rewrite attachments and leave a PDF that opens in one viewer but not another. Repair it before forwarding.
Files copied off a failing drive
A USB stick or memory card that started to fail may have left PDFs with damaged structure. Repair what was copied, and check the result carefully.
A file that breaks other tools
If Merge PDF or a print spooler rejects a document, running it through repair first can produce a cleaner copy that they accept.
Old archives that stopped opening
Documents created by long-gone software sometimes open with warnings today. Rewriting their structure can make them behave in modern viewers.
What repair can and cannot fix
Think of a PDF as a set of objects plus a table of contents for those objects. Repair is good at the second part. If the objects are intact and only the table is broken or missing, rebuilding it is usually enough. If the objects themselves are damaged or absent, there is nothing to point to.
- Usually fixable: a damaged or missing cross-reference table, a truncated end of file, inconsistent object streams.
- Sometimes fixable: files where some pages are damaged. The other pages may come back while the damaged ones are dropped or blank.
- Not fixable: content that was never written to disk, heavily overwritten files and files that were not PDFs to begin with.
- If repair does not help, try re-downloading the file, asking the sender for a fresh copy, or opening it in a different viewer.
Supported formats
- Input
- PDF files (.pdf) with a damaged or unusual structure, up to 200 MB. Encrypted files should be unlocked first.
- Output
- One rebuilt PDF file.
To check a file before or after repair, open PDF Information to see its page count, version and structure.
Good to know
- It cannot recover data that is really missing: a truncated file loses its later pages, and a damaged image stays damaged.
- Not every file can be repaired. If the file is not really a PDF, or its content is largely gone, the tool will report that it could not fix it.
- It repairs structure, not content. It does not fix bad fonts, remove passwords or clean up a file that contains unwanted material.
- Rebuilding rewrites the internal layout, so keep your original in case you need to try another approach.
Your files never leave your browser
This tool runs entirely on your device using your browser. Your files are not uploaded to our servers and are not stored anywhere. Closing the tab discards everything.
Frequently asked questions
Why will my PDF not open?
Most often its internal index is damaged, usually after an interrupted download, a faulty export or a transfer that altered the file. Repair PDF rebuilds that index, which is enough for many files.
Will repairing my PDF lose anything?
The visible pages, text and images should be carried over as they are. If parts of the file were already damaged or missing, they cannot come back. Keep your original and compare the repaired copy against it.
Is my file uploaded to be repaired?
No. QPDF runs as WebAssembly in your browser, so the damaged file is repaired on your device and not uploaded.
How do I know whether the repair worked?
The tool reports whether QPDF found problems and fixed them. Then open the downloaded file and check that all expected pages and images are present.
What if the repaired PDF still looks wrong?
The missing content probably no longer exists in the file. Ask the sender or source for a new copy, or try re-downloading the file over a stable connection.